CULTURE AND REGENERATION OF POPLAR MESOPHYLL PROTOPLASTS

Populus tomentosa is one special species of poplar growing in North China. Mesophyllprotoplasts were isolated from the axenic shoots and cultured in the modified KM8p liquidmedium. Protoplast-derived cells started to divide after 7 days of culture. The frequencyof cell division reached about 20% in 10 days. The yellowish green calli grew compact andnodular after the hormone concentration of medium was adjusted. Shoot formation occurredwhen the protoplast--derived calli were transferred onto MS medium containing zeatin andIAA or NAA. The shoots rooted readily on 1/2 MS hormone--free medium.     

黄磷电炉用硅石的X荧光光谱快速分析

本文选择了硫酸钡为粘合剂,使其高含量硅石能直接粉末压样,应用于黄磷电炉中间控制成份分析,结果满意。     

Picosecond flat-top pulse generation using dual-mode fiber Mach-Zehnder interferometers

We report on an optical fiber Mach-Zehnder interferometer made by offset splicing a dual-mode fiber with two single-mode fibers. The extinction ratio can be tuned from less than 1 dB to greater than 28 dB by rotating the dual-mode fiber along its axial direction. The interferometer is utilized as a pulse shaper to convert a 2.5 ps Gaussian pulse to a 5.2 ps flat-top pulse.     

A new monoterpenoid indole alkaloid from Rauvolfia yunnanensis

One new monoterpenoid indole alkaloid, 11-methoxyburnamine-17-O-3′,4′,5′-trimethoxybenzoate (1), was isolated from Rauvolfia yunnanensis Tsiang. Its structure was identified by spectroscopic evidences.     

OPTIMAL STRATEGY FOR ERADICATION OF MULTIPLE POPULATIONS USING THE STERILE INSECT TECHNIQUE

Sterile insect technique (SIT) provides an attractive alternative to chemical pesticides for insect pest eradication. Because mass rearing facilities are expensive both to construct and to maintain, project managers have a limited number of sterile insects to use in any single eradication campaign. The problem of availability of sufficient numbers of sterile insects can be magnified when two or more independent pest infestations occur at the same time. In this paper we present the results of a modeling study in which dynamic programming is used to compute the optimal allocation strategy for release of sterile insects to control two independent infestations of Mediterranean fruit fly, Ceratitis capitata (Wied.) (medfly). We assume that a fixed number of sterile flies are available per week. Both deterministic and stochastic analyses are presented.     

薯蓣皂素免疫原的合成及其免疫效果分析

采用二环己基碳二亚胺(dicyclohexyIcarbodiimide，DCC)法和水溶性碳二亚胺[1-ethyl-3-(3-dimethy-laminopropyl)carbodiimide hydrochloride，EDC]法，分别将琥珀酸酐化的薯蓣皂素与牛血清白蛋白(bovine serurmalbumin，BSA)偶联，得到不同的免疫原，通过免疫获得兔多克隆抗体，用间接竞争性Dot-ELISA方法分析比较量两种免疫原的免疫效果，结果表明，DCC法合成的薯蓣皂素免疫原免疫效果优于EDC法。     

Defensive and other secretions of the australian cocktail ant, iridomyrmex nitidiceps

Iridodial and isovaleric acid were characterized as major components of the total extract, and of the anal gland secretion, of Iridomyrmex nitidiceps. Minor constituents identified from the total extract included iridolactones, dihydronepetalactones, actinidine, 2- and 3-pentenoic acid, and fatty acids.Behaviour experiments demonstrated isovaleric acid to be primarily an alarm substance, developing repellency only at high concentration. Iridodial was deduced to be the basic repellant. Together the two served a defensive function. Their combination as products of one pair of glands showed a high level of social development.